Bug 1937935 (CVE-2021-21334)

Summary:	CVE-2021-21334 containerd CRI plugin: information leak between containers via environment variables
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	alitke, aos-bugs, bdettelb, bmontgom, bthurber, cnv-qe-bugs, eparis, fdeutsch, gghezzo, go-sig, gparvin, hvyas, jburrell, jokerman, jramanat, jweiser, kaycoth, maszulik, mfojtik, nstielau, o.lemasle, oyahud, phoracek, rphillips, sponnaga, stcannon, stirabos, thee, tomckay
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	containerd 1.3.10, containerd 1.4.4	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in containerd CRI plugin. Containers launched through containerd's CRI implementation that share the same image may receive incorrect environment variables, including values that are defined for other containers. The highest threat from this vulnerability is to data confidentiality.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-28 08:47:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1937936, 1937937, 1938121
Bug Blocks:	1937943

Description Guilherme de Almeida Suckevicz 2021-03-11 18:33:46 UTC

In containerd (an industry-standard container runtime) before versions 1.3.10 and 1.4.4, containers launched through containerd's CRI implementation (through Kubernetes, crictl, or any other pod/container client that uses the containerd CRI service) that share the same image may receive incorrect environment variables, including values that are defined for other containers. If the affected containers have different security contexts, this may allow sensitive information to be unintentionally shared. If you are not using containerd's CRI implementation (through one of the mechanisms described above), you are not vulnerable to this issue. If you are not launching multiple containers or Kubernetes pods from the same image which have different environment variables, you are not vulnerable to this issue. If you are not launching multiple containers or Kubernetes pods from the same image in rapid succession, you have reduced likelihood of being vulnerable to this issue This vulnerability has been fixed in containerd 1.3.10 and containerd 1.4.4. Users should update to these versions.

Reference:
https://github.com/containerd/containerd/security/advisories/GHSA-6g2q-w5j3-fwh4

Upstream patch:
https://github.com/containerd/containerd/commit/05f951a3781f4f2c1911b05e61c160e9c30eaa8e

Comment 1 Guilherme de Almeida Suckevicz 2021-03-11 18:34:09 UTC

Created containerd tracking bugs for this issue:

Affects: epel-7 [bug 1937937]
Affects: fedora-all [bug 1937936]

Comment 3 Przemyslaw Roguski 2021-03-16 14:41:15 UTC

Upstream PR:
https://github.com/containerd/cri/pull/1628/files
https://github.com/containerd/cri/pull/1629/files

Comment 14 Hardik Vyas 2021-04-01 13:43:23 UTC

Statement:

Whilst in OpenShift Container Platform (OCP) there are containers which contain a vulnerable version containerd, they do not import the code from https://github.com/containerd/containerd/tree/master/pkg/cri and hence are not vulnerable to this flaw.

OpenShift Virtualization vendors in containerd in some containers, however none of them depend on it and do not import the code from https://github.com/containerd/containerd/tree/master/pkg/cri and hence are not vulnerable to this flaw.

Red Hat Advanced Cluster Management for Kubernetes (RHACM) includes containerd for the multicloud operators subscription. However, the CRI plugin is not being used in this component, hence RHACM is not affected by this flaw.

Red Hat Quay's builder, and setup operators do make use of the containerd module, but not the vulnerable cri plugin. Therefore they are not affected.